Precipitation Scaling in Extreme Rainfall Events and the Implications for Future Indian Monsoon: Analysis of High-Resolution Global Climate Model Simulations

The increase in water holding capacity of the atmosphere with temperature, given by the Clausius-Clapeyron (CC) relationship, describes the changes in extreme rainfall intensities at warmer atmospheric states. We study the characteristics of extreme rainfall events (EREs) during the Indian summer monsoon season with respect to thermodynamic changes and precipitation-scaling over the Indian subcontinent and its homogeneous rainfall zones. We utilize outputs from a present-day climate simulation and a time-slice future climate change projection experiments of a high-resolution global climate model. Large changes are seen for very EREs (vEREs) which suggests their sensitivity to warmer temperatures. In future, the altered radiative forcing will heat up the upper atmosphere, stabilize it and offset the effect of increasing humidity on precipitation intensity. Our analysis also suggests that more convective clouds and the interplay of increased moisture content and circulation will result in future changes in EREs. The shift in severe rainfall intensities in warmer atmospheric states is explained by the Clausius-Clapeyron (CC) relation, which shows how the atmosphere's ability to hold water increases with temperature. By examining the results of a present-day climate simulation and future climate change projection experiments, we study the characteristics of extreme rainfall events (EREs) during the Indian summer monsoon season with respect to thermodynamic changes. Very EREs (vEREs) are found to increase, suggesting they are sensitive to higher temperatures. The upper atmosphere will warm up in the future, stabilize, and counteract the effect of rising humidity on precipitation intensity. The scaling of precipitation with warming using climate simulations can give information on the regional changes of extreme rainfall eventsVery extreme rainfall events will increase and become highly sensitive to warming in futureWarmer atmosphere favors more convective clouds and a stronger interplay of dynamic-thermodynamic factors